Air-flow-controlling rear housing member

ABSTRACT

An oxygen flow controlling rear housing member for use in a burner comprises a main body portion with a first oxygen inlet. An annular oxygen gathering chamber is in fluid communication with the first oxygen inlet. An annular wall divides the annular oxygen gathering chamber and an annular oxygen-flow mixing chamber. A first oxygen flow passageway extends between the annular oxygen gathering chamber and the annular oxygen-flow mixing chamber, and has a first height that is a portion of the height of the annular wall. A second oxygen flow passageway extends between the annular oxygen gathering chamber and the annular oxygen-flow mixing chamber, and has a second height that is a portion of the height of the annular wall. The height of the first oxygen flow passageway is greater than the height of the second oxygen flow passageway.

FIELD OF THE INVENTION

This application is a non-provisional application claiming priority to U.S. provisional patent application Ser. No. 61/099,200 filed on Sep. 22, 2008.

FIELD OF THE INVENTION

The present invention relates to housing members for use in burners, and more particularly to housing members for use in burners that mix air or oxygen with a gaseous or evaporated fuel.

BACKGROUND OF THE INVENTION

Burners that use gaseous fuel or liquid fuel are used in many applications including boilers, line heaters, furnaces, other gas fired appliances, and in many others. Basically, these burners introduce a gaseous fuel or liquid fuel into a stream of air or oxygen. If liquid fuel is used, it must be vapourized or atomized first. The resulting flow of fuel and air or oxygen is ignited and exits the nozzle of the burner either as a visible flame or as a stream of an extremely hot gaseous mixture.

In an attempt to improve the state of the art units in various applications, such as boilers, line heaters, furnaces, and other gas fired appliances, a detailed study was conducted to qualify and quantify the state of the art in each of these above stated fields. The study indicated that without exception, improvements could be made in each of these areas, especially in terms of reduction of operational costs, and reduction or elimination of emissions. In present world markets, operational costs and environmental concerns, such as reduction or elimination of emissions, are typically two of the most significant issues, if not the most significant issues faced by most businesses.

Interestingly, it is readily apparent in the prior art that the possible improvements that could be made to these various types of devices utilizing burners to produce heat, would not lead to a significantly improved end result. It is also readily apparent that, without exception, the fundamental problem in these various types of devices was that of burner inefficiency. Most prior art burners are only about 60% to 70% efficient. Inefficient combustion of fuel was the main problem inherent with all of these devices. Moreover, this problem of inefficiency of combustion is the major cause of the two above mentioned significant costs in business, namely operational costs and environmental concerns.

Accordingly, in order to fundamentally improve devices such as boilers, line heaters, furnaces, and other gas fired appliances, it has been found that it is necessary to make significant and primary advances to the design of the burners technology. More specifically, in order to maximize the design of boilers, line heaters, furnaces, and other gas fired appliances, in terms of cost, efficiency, and so on, it is necessary to fundamentally re-design the burners that power them. There is no sense in improving boiler technology, line heater technology, furnace technology, and so on, if the burners used in them are prohibitively inefficient.

It is interesting to note that such improvements to various types of burners have been attempted for many years in various areas without significant success. Accordingly, other types of improvements to burner systems and devices that employ burners are commonly used.

The most common design improvement used to overcome the environmental problem of emissions is to recirculate exhaust gases. In general, it has been found that recirculation of the exhaust gases can be used to decrease the overall emissions of a burner system. There are, however, problems associated with such recirculation of the exhaust gases. The most significant problem is that the recirculation of exhaust gases substantially increases the energy required for passing the mixture flow of combustion air and added exhaust gas through the system. For example, an increase of ten percent (10%) of exhaust gas recirculation from the exhaust back to the burner typically results in about a 40% to 45% increase in the required power of the fan that forces air into the burner system. Obviously, this is an attempt at a solution that is less than acceptable in terms of efficiency, and therefore cost. This is especially true considering most exhaust gases are passed through the burner system several times.

There are also burner systems that use energy from high velocity combustion air jets to promote recirculation within the burner system. The effectiveness of this technique depends on many factors, and typically it is more difficult to return a substantial portion of combustion products back to the burner if this technique is used, thus making it difficult to employ in many situations.

It is clear that recirculating exhaust gases in order to improve emissions is not a viable solution to improving the design of burner systems. Burning fuel as efficiently as possible with one pass through the burner system is the only sensible solution; however, desirably efficient burners do not exist.

Only a fundamental re-design of burners and burner technology will produce an efficient burner that produces low emissions. The fundamental technology of burners has not changed significantly in the last several decades. A search of the prior art has revealed two examples of burners that are known to be relatively effective in terms of efficiency and emissions, but not as efficient as the subsequently discussed present invention.

U.S. Pat. No. 7,484,956 issued Feb. 3, 2009, to Kobayashi et al., discloses Low NOx combustion using cogenerated oxygen and nitrogen streams. The combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.

U.S. Pat. No. 7,429,173 issued Sep. 30, 2008, to Lanary et al., discloses a gas burner for use in a furnace and a method of burning gas in a furnace, especially but not exclusively a process furnace used in an oil cracking or refining process. The gas burner comprises two passageways with adjacent outlets. The first passageway is in fluid communication with a source of pressurised fuel gas and has an aperture through which recirculated flue gas can enter the first passageway and the second passageway is in fluid communication with a source of air. In operation, fuel gas is injected into the first passageway and recirculated flue gas is thereby drawn into the first passageway so that it mixes with the fuel gas. Fuel gas is partially combusted and a mixture of partially combusted fuel gas and recirculated flue gas flows up the first passageway and comes into contact with air from the second passageway and combusts. The use of recirculated flue gas keeps down the level of NOx emissions and as the recirculated flue gas is sucked into the first passageway by the pressurised fuel gas flow, it is not necessary to provide complex pumping mechanisms.

U.S. Pat. No. 7,422,427 issued Sep. 9, 2008, to Lifshits, discloses an Energy Efficient Low NOX Burner and Method of Operating Same. The burner is for installation in a furnace having a mixing chamber defined by at least a furnace front wall, two side walls, a top wall and a bottom wall as well as heat transfer pipes through which a heat transfer medium flows and which are arranged on at least one of the top, bottom and side walls. The burner assembly is mounted to the furnace front wall and has a tubular member with an open distal end that is located inside the mixing chamber. The other end of the tubular member is attached to the furnace front wall. Several combustion air ports extend into the tubular member from the other proximal end thereof, and are coupled to a source of combustion air. Several fuel gas discharge nozzles also extend into the tubular member from the other end thereof and are coupled to a fuel source. Furnace gas openings formed in the tubular member are spaced apart from the distal end, are arranged about the tubular member's periphery, and are located relative to the mixing chamber so that furnace gases circulate past some of the heat transfer pipes before they reach the furnace gas openings to thereby form a mixture of combustion air, fuel gas and furnace gas. A spinner at the distal end of the tubular member creates a recirculation zone for the mixture downstream of the spinner and the tubular member.

U.S. Pat. No. 6,485,289 issued Nov. 26, 2002, to Kelly, et al., discloses an Ultra Reduced NOx Burner System and Process. Fuel Modification Fuel Rich Reactor (FMFRR) zone gases are brought together with products from a Fuel Lean Reactor (FMR) zone in a low temperature burnout and NOx reduction reactor zone. The fuel modification fuel rich reactor stabilizes combustion through recirculation of hot gases to the reactants. Nitrogenous species decay reactions in the fuel rich zone controls the production of NOx. The nitrogenous species from the fuel rich zone and the NOx from the fuel lean zone then react in the burnout zone at an optimal temperature and nitrogenous species mix where NOx is minimized. Temperature in all zones, and in particular the burnout zone, can be controlled by furnace gas entrainment, induced flue gas recirculation, forced flue gas recirculation and active cooling by radiative and/or convective heat transfer. NOx can be even further reduced by introducing ammonia, or a like amine species, into the low temperature burnout zone. By balancing combustion and emissions control reactions over several zones, low emissions can be achieved under good flame stability, turndown, heat transfer and noise characteristics.

It is an object of the present invention to provide a air-flow-controlling rear housing member for use in a burner, wherein the air-flow-controlling rear housing member causes the burner to burn fuel very efficiently.

It is another object of the present invention to provide a air-flow-controlling rear housing member for use in a burner, wherein the air-flow-controlling rear housing member causes the burner to produce minimal unwanted emissions.

It is a further object of the present invention to provide a air-flow-controlling rear housing member for use in a burner, wherein the air-flow-controlling rear housing member and burner can be used with various types of gaseous and liquid fuels.

It is a further object of the present invention to provide a air-flow-controlling rear housing member for use in a burner, wherein the air-flow-controlling rear housing member and burner are cost effective.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention there is disclosed a novel oxygen-flow-controlling rear housing member for use in a burner. The oxygen-flow-controlling rear housing member comprises a main body portion having a front end and a back end and defining a longitudinal axis extending between the front end and the back end; a first oxygen inlet in the main body portion; a substantially annular oxygen gathering chamber in the main body portion and in fluid communication with the first oxygen inlet; a substantially annular oxygen-flow mixing chamber within the main body portion; a substantially annular wall generally dividing the substantially annular oxygen gathering chamber and the substantially annular oxygen-flow mixing chamber; a first oxygen flow passageway extending between the substantially annular oxygen gathering chamber and the substantially annular oxygen-flow mixing chamber, and having a first height that is a portion of the height of the substantially annular wall; and a second oxygen flow passageway extending between the substantially annular oxygen gathering chamber and the substantially annular oxygen-flow mixing chamber, and having a second height that is a portion of the height of the substantially annular wall. The height of the first oxygen flow passageway is greater than the height of the second oxygen flow passageway.

Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, the latter of which is briefly described herein below.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features which are believed to be characteristic of the oxygen-flow-controlling rear housing member according to the present invention, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following drawings in which a presently preferred embodiment of the invention will now be illustrated by way of example. It is expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention. In the accompanying drawings:

FIG. 1 is a cut-away side elevational view of the preferred embodiment of the air-flow-controlling rear housing member according to the present invention, installed in a burner;

FIG. 2 is a perspective view of the preferred embodiment of the air-flow-controlling rear housing member installed in the burner as shown in FIG. 1;

FIG. 3 is a side elevational view of the air-flow-controlling rear housing of FIG. 2;

FIG. 4 is a front elevational view of the air-flow-controlling rear housing of FIG. 2;

FIG. 5 is a rear elevational view of the air-flow-controlling rear housing of FIG. 2;

FIG. 6 is a sectional side elevational view of the air-flow-controlling rear housing of FIG. 2, taken along section line 6-6 of FIG. 4;

FIG. 7 is a sectional side elevational view of the air-flow-controlling rear housing of FIG. 1, taken along section line 7-7 of FIG. 4; and,

FIG. 8 is a sectional side elevational view of the air-flow-controlling rear housing of FIG. 1, taken along section line 8-8 of FIG. 3.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Reference will now be made to FIGS. 1 through 8, which show a preferred embodiment of the air-flow-controlling rear housing according to the present invention, as indicated by general reference numeral 30. It should be understood that although for some shapes of burners the determination of front end back and the back end might be somewhat arbitrary, the front end is generally defined as the flame is produced, and the back end is defined as the area where the air and the fuel have their inputs, and where the mixing of the air and the fuel begins.

Reference will now be made to FIGS. 1 through 8, which show a preferred embodiment of the air-flow-controlling rear housing 30 according to the present invention. It should be understood that although for some shapes of burners the determination of front end back and the back end might be somewhat arbitrary, the front end is generally defined as the flame is produced, and the back end is defined as the area where the air and the fuel have their inputs, and where the mixing of the air and the fuel begins.

It should also be understood that for the sake of convenience, the term air is used to describe air received from a pressurized or compressed source of air but that also oxygen from a pressurized or compressed source of oxygen could be used. If a source of air is used, the oxygen in the air is reacted with a fuel such as propane, natural gas, and so on. The nitrogen in the air is merely separated from the oxygen upon combustion. It is also contemplated that hydrogen could be used along with the oxygen.

The air-flow-controlling rear housing 30 comprises a main body 32 having a front end 33 and a back end 34. The longitudinal axis “L” extends between the front end 33 and the back end 34. Preferably, the main body 32 is made from metal, but may be made from any other suitable material.

The air-flow-controlling rear housing 30 further comprises a nozzle receiving passageway 36 in the main body 32. The nozzle receiving passageway 36 is generally centrally disposed in the main body 32 and oriented along longitudinal axis “L”. The air-flow-controlling rear housing 30 also comprises an annular cone portion 37 extending forwardly from the main body 32. The nozzle receiving passageway 36 extends through the annular cone portion 37.

There is at least one air inlet in the main body 32, and in the preferred embodiment, as illustrated, there is a first air inlet 38 and a second air inlet 39 in the main body 32, specifically in the rear housing 32. The first air inlet 38 and the second air inlet 39 are spaced one hundred eighty degrees) (180°) apart in order to effectively maximize the subsequent mixing of air flow. The first air inlet 38 and the second air inlet 39 are each oriented generally along the longitudinal axis “L”, as shown, but could alternatively be oriented at another angle. It is contemplated that there may also be additional air inlets in said main body 32 to accommodate the need for additional air input.

It should also be noted that in an alternative embodiment, there could be additional inlets for introducing a secondary type of fuel, such as hydrogen and even including the un-burnt emissions from other types of burners, and the like.

The air-flow-controlling rear housing 30 comprises a substantially annular air gathering chamber 29 in the main body portion 32. The substantially annular air gathering chamber 29 is in fluid communication with the first air inlet 38 and the second air inlet 39. The substantially annular flow passage is substantially circular in shape.

There is also a substantially annular air-flow mixing chamber 100 within the main body portion 32. The substantially annular air-flow mixing chamber 100 is also substantially circular in shape.

A substantially annular wall 110 generally divides the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100. The substantially annular wall 110 is substantially circular in shape.

The substantially annular air gathering chamber 29 generally surrounds the substantially annular air-flow mixing chamber 100. The height of the substantially annular air gathering chamber 29 and the height of the substantially annular air gathering chamber 100 are similar one to the other. Further, the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100 are substantially longitudinally aligned one with the other along the longitudinal axis “L”.

The first air inlet 38 and the second air inlet 39 are disposed rearwardly of the substantially annular air gathering chamber 29 in order to cause properly directed forward flow of air into the air gathering chamber 29. Further, in this manner, the fittings that connect the air lines to the first air inlet 38 and the second air inlet 39 do not project laterally outwardly, which might be unsafe.

A first air flow opening 101 extends between the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100. The first air flow opening 101 has a first height that is a portion of the height of the substantially annular wall 110. There is also a second air flow opening 102 that extends between the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100. The second air flow opening 102 has a second height that is a portion of the height of the substantially annular wall 110. The height of the first air flow opening 101 is greater than the height of the second air flow opening 102.

The burner 20 further comprises a third air flow opening 103 extending between the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100. The third air flow opening 103 has a third height that is a portion of the height of the substantially annular wall 110. The height of the first air flow opening 101 is greater than the height of the third air flow opening 103, and the height of the second air flow opening 102 is greater than the height of the third air flow opening 103.

The burner 20 also further comprises a fourth air flow opening 104 extending between the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100. The fourth air flow opening 104 has a fourth height that is a portion of the height of the substantially annular wall 110. The height of the first air flow opening 101 is greater than the height of the fourth air flow opening 104. The height of the second air flow opening 102 is greater than the height of the fourth air flow opening 104. The height of the third air flow opening 103 is greater than the height of the fourth air flow opening 104.

It has been found that having different heights of the first air flow opening 101, the second air flow opening 102, the third air flow opening 103 and the fourth air flow opening 104 produces an effective dynamic flow mixture of the air entering the substantially annular air-flow mixing chamber 100.

It is further contemplated that in another embodiment of the present invention, the first, second, third and fourth air flow openings could be oriented at an angle such that air flowing therethrough enters the substantially annular air-flow mixing chamber 100 obliquely, thereby helping to create annularly swirling flow patterns in the substantially annular air-flow mixing chamber 100.

In use, air enters the air-flow-controlling rear housing 30 through the first air inlet 38 and a second air inlet 39, and first gathers in the substantially annular air gathering chamber 29. The air passes from the substantially annular air gathering chamber 29 to the substantially annular air-flow mixing chamber 100 via the first air flow opening 101, the second air flow opening 102, the third air flow opening 103 and the fourth air flow opening 104. The offset depths of the first air flow opening 101, the second air flow opening 102, the third air flow opening 103 and the fourth air flow opening 104 cause the air to enter the substantially annular air-flow mixing chamber 100 at four distinct and separate “levels” (with respect to the longitudinal axis “L”), thus causing non-laminar flow of the air. In this manner, the air is as turbulent as possible in order to facilitate full mixing of the air downstream with fuel from the fuel nozzle tip 60.

As can be understood from the above description and from the accompanying drawings, the present invention provides a air-flow-controlling rear housing member for use in a burner that burns fuel very efficiently, that produces minimal unwanted emissions, that can be used with various types of gaseous and liquid fuel, and that is cost effective, all of which features are unknown in the prior art.

Other variations of the above principles will be apparent to those who are knowledgeable in the field of the invention, and such variations are considered to be within the scope of the present invention. Further, other modifications and alterations may be used in the design and manufacture of the fuel nozzle of the present invention without departing from the spirit and scope of the accompanying claims. 

1. An air-flow-controlling rear housing member for use in a burner, said air-flow-controlling rear housing member comprising: a main body portion having a front end and a back end and defining a longitudinal axis extending between said front end and said back end; a first air inlet in said main body portion; a substantially annular air gathering chamber in said main body portion and in fluid communication with said first air inlet; a substantially annular air-flow mixing chamber within said main body portion; a substantially annular wall generally dividing said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber; a first air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a first height that is a portion of the height of said substantially annular wall; and, a second air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a second height that is a portion of the height of said substantially annular wall; wherein the height of said first air flow opening is greater than the height of said second air flow opening.
 2. The air-flow-controlling rear housing member of claim 1, further comprising a third air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a third height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said third air flow opening, and the height of said second air flow opening is greater than the height of said third air flow opening.
 3. The air-flow-controlling rear housing member of claim 2, further comprising a fourth air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a fourth height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said fourth air flow opening, the height of said second air flow opening is greater than the height of said fourth air flow opening, and height of said third air flow opening is greater than the height of said fourth air flow opening.
 4. The air-flow-controlling rear housing member of claim 1, wherein said made body portion is made from metal.
 5. The air-flow-controlling rear housing member of claim 1, further comprising a second air inlet, and wherein said substantially annular air gathering chamber is in fluid communication with said second air inlet.
 6. The air-flow-controlling rear housing member of claim 1, wherein said substantially annular air gathering chamber is substantially circular in shape.
 7. The air-flow-controlling rear housing member of claim 6, wherein said substantially annular wall is substantially circular in shape.
 8. The air-flow-controlling rear housing member of claim 1, wherein said wherein the height of said substantially annular flow passage and the height of said air gathering chamber are similar one to the other.
 9. The air-flow-controlling rear housing member of claim 1, wherein said substantially annular air gathering chamber generally surrounds said substantially annular air-flow mixing chamber.
 10. The air-flow-controlling rear housing member of claim 9, wherein said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber are substantially longitudinally aligned one with the other along said longitudinal axis.
 11. The air-flow-controlling rear housing member of claim 1, wherein said first air inlet is disposed rearwardly of said substantially annular air gathering chamber.
 12. The air-flow-controlling rear housing member of claim 11, wherein said first air inlet is oriented generally along said longitudinal axis.
 13. The air-flow-controlling rear housing member of claim 1, further comprising a second air inlet in said main body portion, and wherein said substantially annular air gathering chamber is in fluid communication with said second air inlet.
 14. The air-flow-controlling rear housing member of claim 13, wherein said second air inlet is disposed rearwardly of said substantially annular air gathering chamber.
 15. The air-flow-controlling rear housing member of claim 14, wherein said second air inlet is oriented generally along said longitudinal axis.
 16. The air-flow-controlling rear housing member of claim 1, further comprising a nozzle receiving throughpassage in said main body portion.
 17. The air-flow-controlling rear housing member of claim 16, wherein said nozzle receiving throughpassage is generally centrally disposed in said main body portion and oriented along said longitudinal axis.
 18. The air-flow-controlling rear housing member of claim 17, further comprising an annular cone portion extending forwardly from said main body portion.
 19. The air-flow-controlling rear housing member of claim 18, wherein said nozzle receiving throughpassage extends through said annular cone portion. 